Saved Bookmarks
| 1. |
If the amplitude of a wave at a distance `r` from a point source is `A`, the amplitude at a distance `2 r` will beA. AB. 2AC. `A//2`D. `A//4` |
|
Answer» Correct Answer - C Intensity = Energy/Sec/Area = Power/Area. From a point source, energy spreads over the surface of a sphere of radius r. `:.` Intensity `=P/A=P/(4pi r^(2)) prop 1/r^(2)` But intensity = `("Amplitude")^(2)` `:. ("Amplitude")^(2) prop 1/r^(2)` or Amplitude `prop 1/r` At distance 2r, amplitude becomes `A//2` |
|